SW Sim09 Meshing Help
SW Sim09 Meshing Help
(OP)
Hello Gents,
I am attempting to create a stronger wire basket. I would like to use simulation to find the stress points for said basket. However I cannot get the program to mesh the model. I have created the model as one solid part. I have merged all bodies into one solid body. After the comp attempts to mesh the body, it tells me that the surface mesh is successful but the volume mesh has failed and that I should try a smaller element size for meshing. I have scaled the model up to four times where the larger wire diameter is now 1.250in and the element size is .00186in and yet the program still asks for a smaller element size. Is there any thing I can maybe do different?
I am attempting to create a stronger wire basket. I would like to use simulation to find the stress points for said basket. However I cannot get the program to mesh the model. I have created the model as one solid part. I have merged all bodies into one solid body. After the comp attempts to mesh the body, it tells me that the surface mesh is successful but the volume mesh has failed and that I should try a smaller element size for meshing. I have scaled the model up to four times where the larger wire diameter is now 1.250in and the element size is .00186in and yet the program still asks for a smaller element size. Is there any thing I can maybe do different?






RE: SW Sim09 Meshing Help
corus
RE: SW Sim09 Meshing Help
RE: SW Sim09 Meshing Help
RE: SW Sim09 Meshing Help
Foofire
CSWP
RE: SW Sim09 Meshing Help
AFAIK there is no way to directly control joints and connections.
You can have some control over them by changing joint clearence value (the same for all joints, so not much of a control). It will be a trial and error work until you have the model that pleases you.
You can also delete joints from de Result window, which adds more control.
Joints between 2 members are represented by violet spheres. Beams ends are rpresented by greyed green spheres. You must check if colors are according to model or if you dont have a sphere where it was suppose to be and vice-versa. If one of these erros occours, you need to adjust the joint clearence.
Smaller joint clearence values have the effect of missing joints. Bigger joint clearence have the effect of considering some joints of smaller menbers as one. So I guess that you must have the smaller joint clearence that provides you a good model.
One trick: in order to have a correct rebuild of the
model between 2 joint clearences, meke a dumb joint clearence with a big value in the middle.
I hope this hepls you.
Regards
RE: SW Sim09 Meshing Help
What result are you after? Stress in the spot welds? Deflection? Possible yielding of the wire?
TOP
CSWP
BSSE
www.engtran.com
www.niswug.org
"Node news is good news."
RE: SW Sim09 Meshing Help
"surface mesh is successful but the volume mesh has failed" indicates that the mesh tolerance was high enough to cause volume elements to collapse. You can try:
1. Decrease global element size
2. Decrease tolerance (even to .000001 to see if it will work).
3. Try curvature-based mesher.
You'll need a bit of RAM to do this one!
RE: SW Sim09 Meshing Help
Foofire
CSWP
RE: SW Sim09 Meshing Help
TOP
CSWP
BSSE
www.engtran.com
www.niswug.org
"Node news is good news."
RE: SW Sim09 Meshing Help
Foofire
CSWP
RE: SW Sim09 Meshing Help
Model the bottom of the basket and look at the effect of loading patterns.
Take the reactions from the bottom and apply them to the sides. And model just the sides.
Then apply the side reactions to the support frame.
Use symmetry to reduce the problem size.
You might also consider finding an equivalent shell thickness and replace the wire with shells? When FEA first started this was done alot.
TOP
CSWP
BSSE
www.engtran.com
www.niswug.org
"Node news is good news."
RE: SW Sim09 Meshing Help
Foofire
CSWP
RE: SW Sim09 Meshing Help
Any plates and shells book will probably do an approximation of a shell with beam elements. You would just be working backwards.
TOP
CSWP
BSSE
www.engtran.com
www.niswug.org
"Node news is good news."
RE: SW Sim09 Meshing Help
This software is not some mickey mouse product, and the meshing problems are global, not limited to wire baskets.
The help is pathetic.
RE: SW Sim09 Meshing Help
This is a case of trying to let the software dictate how to solve the problem. The developers of Simulation have chosen to limit the tools to what the masses can understand rather than give the wide choice of elements and options that more complete FE software contains. However, Cosmos/M is included with Simulation, is a complete FE solution and can be used to create a beam mesh at the expense of requiring the user to understand the problem to a greater extent than Simulation.
The reason the experienced FE users are pointing the OP away from proceeding down the path of solid meshing is that it creates a HUGE model that is difficult to mesh, takes a long time to solve, if it will mesh and solve at all. A beam mesh on the other hand will take considerable less time to solve and will give just as good an answer. The same is true of an equivalent shell mesh.
TOP
CSWP, BSSE
www.engtran.com www.niswug.org
"Node news is good news."